Support is requested for acquisition and upgrading of a Meridian ACAS 470 laser cytometer for analysis of attached cells in culture. The instrument will be used extensively by cell biologists and neuroscientists at Wayne State University who utilize cultured cell immunofluorescent labeling and their studies. A group of six NIH-funded users will utilize the facility a majority of the time and oversee its operation for other users. Their specific projects are as follows: (1) DR. Robert Skoff, Principal Investigator, will utilize the laser cytometer to analyze differentiation and proliferation of astroglia and oligodendroglia in culture in normal mice and a myelin deficient mutant, jimpy. (2) Dr. Joyce Benjamins, Co-Principal Investigator, will examine alterations in membrane assembly and cytoskeletal organization of cultured oligodendroglia induced by antibodies to surface glycolipids and changes in intracellular Ca++ and pH. (3) Dr. Gregory Kapatos will examine the relationships between electrical activity, tyrosine hydroxylase levels and intracellular Ca++ in cultured dopaminergic neurons from embryonic rat mesencephalon. (4) Dr. Tuan Kuo analyze the role of the Ca++ pump and the involvement of the Ca++ signal in cell activation, using cultured rat aortic smooth muscle cells stimulated by the agonist angiotensin II. (5) Dr. Robert Lisak will examine the effects of cytokines on the proliferation and differentiation of cultured Schwann cells from rat PNS. (6) Dr. Arun Wakade will examine the contribution of second messengers in release of catecholamines from peripheral neurons and adrenal chromaffin cells, with emphasis on the role of Ca++.